NR6893 Sulfanilic Acid Powder

Sulfanilic Acid Powder Description

Sulfanilic Acid Powder crystallizes as monoclinic prisms or fine powder with a molecular weight of 173.19 g/mol and decomposition at 288°C. The para-aminobenzenesulfonic acid structure provides dual functional groups (-NH₂ and -SO₃H) that enable electrophilic substitution and diazotization reactions. It exhibits limited solubility in cold water (0.5% w/v at 20°C) but dissolves readily in hot water (5% w/v at 100°C) and alkaline solutions, forming water-soluble salts. Insoluble in ethanol and nonpolar solvents. Technical grades maintain strict impurity controls: aniline ≤0.1%, sulfate ash ≤0.05%, heavy metals (Pb ≤5 ppm), and moisture ≤0.5%. UV-Vis spectra show λₘₐₓ at 254 nm in neutral solutions, shifting to 290 nm under alkaline conditions.

Sulfanilic Acid Powder Applications

Dye Manufacturing: Primary intermediate for Congo Red, Methyl Orange, and acid azo dyes via diazotization-coupling reactions.

Analytical Chemistry: Chromogenic reagent for nitrite detection (Griess test) at 0.5–10 ppm sensitivity; urinary glucose test component.

Photography: Antioxidant in color developer solutions (0.1–0.5% w/w) to prevent oxidation of developing agents.

Corrosion Inhibition: Precursor for sulfanilamide-based metal passivators in cooling water systems.

Sulfanilic Acid Powder Packaging

Our products are packaged in customized cartons of various sizes based on the material dimensions. Small items are securely packed in PP boxes, while larger items are placed in custom wooden crates. We ensure strict adherence to packaging customization and the use of appropriate cushioning materials to provide optimal protection during transportation.

Packaging: Carton, Wooden Box, or Customized.

Kindly review the packaging details provided for your reference.

Manufacturing Process

1.       Testing Method

(1)    Chemical Composition Analysis - Verified using techniques such as GDMS or XRF to ensure compliance with purity requirements.

(2)    Mechanical Properties Testing - Includes tensile strength, yield strength, and elongation tests to assess material performance.

(3)    Dimensional Inspection - Measures thickness, width, and length to ensure adherence to specified tolerances.

(4)    Surface Quality Inspection - Checks for defects such as scratches, cracks, or inclusions through visual and ultrasonic examination.

(5)    Hardness Testing - Determines material hardness to confirm uniformity and mechanical reliability.

Please refer to the SAM testing procedures for detailed information.

Sulfanilic Acid Powder FAQs

Q1. Why does the powder turn pink during storage?

Oxidation of the amine group forms quinoid structures upon air exposure. Store under inert gas or with oxygen scavengers; discoloration does not affect diazotization reactivity if free aniline ≤0.2%.

Q2. How to dissolve it completely for the Griess reagent?

Suspend in 1% HCl at 60°C for 15 minutes, then add sodium acetate to neutralize. Solubilizes via zwitterion formation at pH 4–6.

Q3. Is it regulated as a hazardous substance?

Classified as H315/H319 (skin/eye irritation) under GHS. Use NIOSH-approved respirators if airborne dust exceeds 5 mg/m³; no carcinogenicity (IARC Group 3).

Related Information

1.       Common Preparation Methods

Sulfanilic Acid is synthesized by sulfonating aniline with concentrated sulfuric acid at 180–200°C for 5–8 hours. The molten mixture is quenched in water, and crude crystals are collected via filtration. Purification involves dissolving in boiling water with activated carbon treatment, followed by recrystallization at pH 3–4. The dihydrate form is dehydrated at 100°C under vacuum to yield anhydrous powder, milled to 80% particle size <150 μm, and packaged with desiccants.